What constitutes "freezing" the interferon?

i know i'm supposed to keep the interferon not freeze but stay cold. My refrigerator is running way to cold and i can't afford to fix it. Would i be able to tell if the interferon is still ok to use if the liquid moves around and appears to not have any ice in it? I know it's in a vacummmn....what would that have on the effects of using interferon that may have been frozen.Do you think it might be better that i put my interferen in a cooler with ice-paks and monitor the temperature with a thermoneter? I'm been feeling that my leaving the interferon in the fridge that gets really cold might be affecting the interferon...even tho i've notice no ice or freezing of the liquid...maybe this has somethig to do with the vacummn in the vial. thanks, all.....thrak